Hope for new TB jab slashed after trial failure

The fight against tuberculosis (TB) has suffered a major setback after the most advanced experimental vaccine missed efficacy targets in human trials.

The vaccine MVA85A, developed by researchers at Oxford University, did not offer extra protection against the disease in babies already vaccinated with BCG.

The Phase IIb clinical trial, involving 2,800 babies in South Africa and published in The Lancet, was the first to assess the ability of a new TB vaccine to prevent the disease since BCG, which has been around for some 90 years.

There is an urgent need to find effective vaccines as BCG is only partially effective against the TB bacterium, it does not prevent TB affecting the lungs, the most common form of the disease in adolescents and adults.

But despite the disappointing results, "getting to this point marks a step forward for the field and there is much to be learned from the results," commented Professor Helen McShane, who developed MVA85A.

"The results from this study should let us know far more about the type and level of immune response required, and that will boost future efforts to develop an effective TB vaccine by Oxford and other researchers throughout the world," she added.

And in an accompanying editorial, Christopher Dye of the World Health Organisation and Paul Fine from London School of Hygiene and Tropical Medicine also note that the results are not "a terminal prognosis" for MVA85A, nor for other jabs in development, including those at Johnson & Johnson group Crucell and GlaxoSmithKline.

TB is the second leading infectious disease killer in the world, with 8.7 million cases and 1.4 million deaths In 2011.